Aerosol insecticide bomb



April 15, 1952 METZGER 2,593,165

AEROSOL INSECTICIDE BOMB Filed Sept. 30, 1 948 F IG.I

x v 11 r L :1

ATTORNEY Patented Apr. 15, *1952 UNITED STATES PATENT OFFICE 2,593,165 7 AEROSOL INSECTICIDE BOMB Floyd J. Metzger, New York, N. Y.

Application September 30, 1948, Serial No. 52,034 20mins. (Cl. 299-95 This invention relates to aerosol insecticide bombs, and particularly to improvements therein whereby filling of the bomb is accomplished readily so that the bomb 'may be used repeatedly.

Aerosol bombs containing solutions of insecticides and insectifuges are well known. The bomb mustbe made of metal of substantial strength to withstand internal pressure. form, these bombs are discarded after the contents are discharged, a wasteful procedure, since the bomb container is relatively expensive. Refillable bombs have been developed, but these must be returned to the factory for charging, thus involving another economic waste.

Moreover, the solutions used in aerosol bombs are not adapted to effect the best results and are in fact harmful when applied to plant life and to other materials. The usual solvent employed is difluorodichloromethane, commonly known as Freon 12. Freon is not a good solvent for the active agents. It is necessary, therefore, to add or more of a solvent such as a hydrocarbon oil in which the active agents are soluble. Such oils are objectionable because they stain objects upon which the spray is directed. Also, such a except with special equipmentand by persons skilled in handling such material.

It is the object of the present invention to provide an improved aerosol insecticide bomb which can be refilled with solutions of insecticides or insectifuges and charged with a gas such as carbon dioxide under pressure.

Other objects and advantages of the invention will be apparent as it is better understood by reference to the following specification and the accompanying drawing, in which Fig. l is a longitudinal section through an aerosol bomb embodying my invention;

Fig. 2 is a plan view of the release mechanism for the bomb;

Fig. 3 is a section on the line 3--3 of Fig. 2;

Fig. 4 is a section on the line 4-4 of Fig. l; and

Fig. 5 is a section on the line 5--5 of Fig 4.

I have discovered that excellent results can be obtained by dissolving the active agents in a simple solution such as acetone, which is liquid at atmospheric temperature and pressure. Such a solution may be introduced readily to a suitable container or bomb by anyone without the use of special apparatus or skill. To afford the pressure In the common necessary to expel the solution as a spray, the solution in the container or bomb is charged with a gas such as carbon dioxide. This is easily accomplished by using a capsule containing liquid carbon dioxide which'is available in commerce. The capsule is-punctured by means attached to the container or bomb and the gas is introduced to the solution through a check valve which prevents escape of the gas when the capsule is exhausted. The gas thus introduced affords sulficient pressure within the container or bomb to expel the liquid when the outlet valve is released and the spray can be directed to the place of application. The solution carrying the active ingredients is thus discharged until the pressure is exhausted. Thereupon the container or bomb can be opened and recharged with the solution and with the gas as often as may be required.

The solvents such as acetone are harmless to plant life, do not stain materials to which the spray is applied, and otherwise are harmless. Because of the content of carbon dioxide in the spray, the resulting vapors are non-inflammable. even though the solvent itself may be inflammable. Thus the insecticide bomb affords numerous advantages over bombs as heretofore known.

Nevertheless it is both inexpensive and quite as effective as any of such devices.

Any insecticide or insectifuge which is soluble in the solvents employed may be utilized. Those commonly used are pyrethrins, rotenone, piperine (extract of black pepper) and dichlorodiphenyl trichlorethane, commonly known as DDT. These active agents and others of a similar nature, as well as mixtures thereof, may be utilized in accordance with my invention.

As a solvent for the active agents, I utilize materials which are liquids at normal atmospheric pressure and temperature but have low boiling points, i. e., below C. at normal atmospheric pressure, and high vapor pressures, i. e. above 50 mm. Hg at 20 C., so that the liquids evaporate with great rapidity when discharged in the form of fine spray into the atmosphere. The following examples of suitable solvents will illustrate the type of solvents to which I refer:

These solvents are relatively pure chemical compounds readily obtainable in commerce and relatively cheap. They leave no measurable residues when evaporated and do not injure materials or vegetation to which the composition may be applied.

The selected active agents are dissolvedin the selected solvent. Since they are readily' soluble, it is not necessary to add oils such as petroleum oils in order to maintain the solutions. The solution is then introduced to the bomb, which is thereafter charged with carbon dioxide to the desired pressure resulting from discharge into the bomb of carbon dioxide from standard capsules containing approximately 8 to 9 grams or more of liquid carbon dioxide. The bomb is then ready for use.

The carbon dioxide serves several purposes. First, the pressure forces the liquid through a pipe extending from a point adjacent the bottom of the bomb to the orifice, and thence through the orifice when the valve is released, thereby .spraying the liquid into the atmosphere in a finely divided form. Second, the carbon dioxide is quite freely soluble in the solvents employed and, because of the large amount of dissolved carbon dioxide, the stream or spray issues with explosive force, thereby atomizing the spray into an extremely fine state of subdivision which is fog-like in appearance. Third, the presence of such large proportions of carbon dioxide in the vapors as they issue from the bomb makes the jet non-inflammable even though the solvent may be inflammable.

- Another advantage of the compositions as described is that the solvents employed have low boiling points and highvapor pressures at ordinary atmospheric temperatures and pressures, and therefore evaporate with great rapidity. The spray can be directed upon any surface without leaving an oily residue, and it is particularly desirable in spraying vegetation, since there is no oily residue to injure plants.

Referring to the drawing, indicates a container or bomb which may be made of metal having sufficient strength to withstand the internal pressure. It should be noted that pressures such as those resulting from the use of Freon are not attained in the use of the present inventiomand consequently a bomb of much lighter metal may be used. The precise form of the container 5 is unimportant, but it is preferably cylindrical, with dished ends 6 and I securely held to seal the ends of the bomb. Conveniently a handle 8 may be provided to facilitate the use of the bomb.

The head 6 is provided with an inlet opening 9 which is sealed by a cap 10 threadedly or otherwise secured to facilitate filling of the bomb.

The filling opening 9 may be disposed in the dished end 6 or otherwise.

A tube ll extends from a point adjacent the edge of the dished end 1 through the dished end 6, being threadedly or otherwise mounted in an opening in the dished end 6 and held by a nut or boss I2. This tube ensures discharge of all of the liquid under-pressure in the bomb. Connected to the end of the tube II is a nipple l3 containing the outlet valve mechanism. Any suitable valve may be used, but conveniently an ordinary air tire valve will serve the purpose. As shown in Fig. 3, such a valve comprises a stem M loosely and slidably supported in a member which is threadedly mounted in the nipple l3 and carries a valve l6 co-operating with a seat H. The end of the stem I4 is loosely mounted in a spacing member I8 which rests on the bottom IQ of the nipple I 3. A spring is disposed between a shoulder 2| on the spacing member l8 .and a 4 valve member 22 which is adapted to engage a seat 23. The valve member 22 normally is held closed by the spring 20. However, when the stem I4 is depressed, the valve member 22 ,is carried away from the seat, permitting flow of fluid upwardly through the valve and around the stem [4. The fluid in the present case is discharged through a capillary passage 24 in the form of a fine spray.

To actuate the stem [4, a lever 25 is pivoted at 26 in a bracket 21 and has a depending portion 28 engaging a diaphragm 29 which seals the upper end of the nipple l3. When the lever 25 is depressed, the diaphragm 29 and the stem l4 are similarly depressed to permit escape of the fluid from the bomb through the capillary passage 24. Thus the spray may "be directed upon the surfaces or into the space desired.

In order to permit charging of the bomb witha gas under pressure such as carbon dioxide, a nipple 30 is threadedly or otherwise secured to the dished end 1 and held by a cap 3| within the bomb. Threadedly mounted within the nipple 30 is a member 32 having an extension 33 which is hollow and is provided with a sharpened end 34. A valve member 35 of rubber or similar material is mounted above the member 32 and is provided with a minute slit or opening 36 which permits the inward passage of gas under pressure but prevents return flowof the gas because the resiliency of the rubber causes the slit 39 to close whenever the pressure of the entering gas falls below the pressure of the gas within the bomb. A ferrule 31 of rubber or othersuitablematerial is disposed in the nipple on the opposite side of the member 32 and is held in place by a split ring 38.

A member 39, having wings 40 and a recess for a capsule 4| is adapted to threadedly engage the nipple 39. The capsule 4i rests in the recess and is'held by the abutment 42 at the end of the member 39. Thus, as the member 39 is turned on the nipple 30, it is forced inwardly and the member 32 pierces a diaphragm at the end of the capsule 4|, permitting discharge of the liquid carbon dioxide under pressure through the member 33 and the opening or slit 36 into the interior of the bomb, thereby charging the liquid contents with the gas.

In utilizing the device, the cap I0 is first removed and the bomb is nearly filled with the previously prepared solution of the active agents in the solvent. The cap is then replaced and the member 39, with the capsule 4| .therein, is manipulated to introduce the gas under pressure to the solution. When the capsule is completely discharged, the member 39 may be separated from the bomb, which is then ready for use. By depressing the lever- 25, the solution may be discharged in the manner hereinbeforeindicated.

Various changes may be made in the details of the construction and arrangement of the parts without departing from .the invention or sacrificing the advantages thereof.

Iclaim:

1. An aerosol insecticide bomb comprising a receptacle having upper and lower ends and a filling opening, a closure for the filling opening, an outlet tube extending .through the upper end and to a point adjacent the lower end within the receptacle, a valve within said tube, a flexible diaphragm extending entirely across and sealing the upper end of said tube, means positioned outwardly of the diaphragm and acting against the outer side thereof for actuating the valve, said tube having a capillary opening between the 2. An aerosol insecticide bomb as defined in claim 1 in which the valve means of the inlet connection comprises a resilient member inwardly of the piercing member and having a slit to permit the passage of a gas from a capsule of liquefied gas into the receptacle, and pressure within the receptacle normally acts on the resilient member to maintain the slit closed against backward fiow of contents of the receptacle through the slit.

FLOYD J. METZGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Altmann Nov. 21, 1933 Campbell .Jan. 22, 1935 Seat Oct. 8, 1935 Iddings Feb. 9, 1937 Brewer Dec. 5, 1939 Smith -May 5, 1942 Threm Sept. 7, 1943 Ward June 13, 1944 Goodhue Dec. 17, 1946 Simanton Jan. 12, 1951 

